I – Name

The name of the association shall be the American Shark Association.

II – Insignia

The emblem of the class shall be as shown below:

III – Object

The object of the association shall be to promote and govern Shark Catamaran racing under uniform rules.

IV – Organization

The powers of the association shall be vested in the Governing Committee. The Governing Committee shall be constituted, and elected or appointed, as provided in the by-laws.

V – Districts and Fleets

1. The governing committee shall establish geographical districts.

2. A fleet shall consist of three or more boats within a given district.

3. Fleet charters shall be granted by the governing committee upon appropriate application.

4. District and Fleet officers shall be as provided in the by-laws.

VI – Dues

Association dues and taxes shall be fixed by the by-laws.

VII – Membership

There shall be three classes of membership as follows:

1. Active: An active member may vote and hold office. He shall be an owner or part owner of a Shark.

2. Associate: An associate member is a non-owner of a Shark who is interested in the welfare of the class. He may not vote or hold office.

3. Lifetime: A member who has been honored due to extraordinary service to the association and who has been exempted from paying dues. He may not vote or hold office unless he is an owner or part owner of a Shark.

All members will receive the class publication.

VIII – Annual Meeting

An annual meeting shall be held at a time and place fixed by the Governing Committee, which shall whenever possible be during the period of and in the vicinity of the Association championship.

Except where otherwise specified in this Constitution a majority of those votes present shall decide all questions. The Governing Committee may, at its discretion, require ratification of any measures by a mail vote of the membership.

Order of Business:

1. Call to order

2. Reading of minutes

3. Report of actions of the Governing Committee

4. Other reports

5. Unfinished business

6. New business

7. Election of officers

8. Adjournment

IX – Amendments

Amendments to the Constitution and to the by-laws covering measurement may be made by the following procedure:

An amendment must be moved, seconded and passed by a majority vote at the annual meeting. The proposed amendment shall then be submitted to the membership by mail. Enactment requires a two-thirds majority of all ballots filed.


1. Association Officers shall be:

(a) President, Secretary, and Chief Measurer. They shall serve a term of two years.

(b) Elections will be held at the Annual Meeting.

(c) The President, Secretary, and Chief Measurer shall comprise the Governing Committee. The designer and professional builders shall be technical advisers.

2. District Secretary and District Measurer

(a) The District Secretary shall have jurisdiction over all Shark activities in his district. He shall be appointed annually by the Governing Committee.

(b) The District Measurer shall be appointed by the Governing Committee. He shall be available, at his convenience, to measure and certify boats and sails.

(c) Fleet Officers shall consist of a Captain and a Secretary, and shall be elected by the fleet annually.

3. Flag and Honor Awards

(a) The Flag of the association shall be the insignia, with the letters ASA in black beneath the black shape.

(b) Honor awards may be worn on sleeves of Yachting or mess jackets, and must be displayed on the sail.

Awards rank in the following order:

Association Championship: Gold

District Championship: Red

Sanctioned Event: Blue

Only the highest award ever won shall be displayed.

4. Dues

Dues shall be $30 per year for active members (boat owners) and $15 annually for associate members (non-owners, crews, etc).

5. Identification

(a) Each yacht shall be identified by a builders serial number cut or burned in to the wood of the rear beam inside the starboard hatch, or dyed into the hull laminate below the starboard hatch.

(b) Sail numbers shall be displayed upon the sail. Sail numbers may be exchanged between boats by owners mutual consent upon payment of $10.00 re-registration fee to class Secretary.

(c) Name of boat, builders serial number, and sail number shall be recorded with the Association.

6. Measurement

No yacht shall be eligible to enter any race until it has been granted a measurement certificate and sails have been measured and stamped.

Measurement certificates will be issued automatically to boats constructed by builders franchised by the designer. Once annually, or more often at his discretion, the Chief Measurer or his designated representative will measure a new production boat to ensure continuing quality control.

Measurement certificates will be issued by the Chief Measurer.

They may be protested upon the deposit of $50.00 with an association officer, refundable if the protest is upheld. All such protests will be heard by the Governing Committee.

7. Rules

Rules of the IYRU shall govern all Shark Events.

8. Racing Restrictions

(a) Racing crew shall be at least two persons wearing appropriate dry clothing.

(b) Each boat must carry a suitable anchor, fifty feet of line, paddle, and a wearable life jacket.

(c) A whisker pole may be used.

(d) The same crew must sail in all races of a given regatta. In case of emergency, reasonable substitution may be permitted by the race committee.

(e) The same sails must be used in all races of a given regatta. In case of damage, substitution may be permitted by the race committee. Battens may be changed as desired.

9. Liaison Committee

The President of the ASA and one member appointed by the Governing Committee shall constitute the American members of the International Liaison Committee.

It shall be their duty with their foreign counterparts to coordinate the affairs of the various national associations.

Membership in any national association shall entitle the member to all rights and privileges in other national associations except voting. A regatta fee may be charged for district or national events.

10. Specifications

It is the interest of this organization to preserve the one-design character of the Shark Catamaran in order to ensure uniform equipment in competition and, so far as possible, to delay obsolescence of individual boats.

Since the design of the Shark Catamaran is the creation and property of J. Roderick Macalpine-Downie, this association can claim no rights to cause any changes in dimensions or construction of the Shark Catamaran.

It is the understanding of this association that the designer and his franchised professional builders intend to make no fundamental modifications to design or construction which would affect performance.

On the other hand it is clearly advantageous to adopt new materials or methods which could render the boat stronger, more durable, easier to manufacture, or cheaper. It is therefore agreed that this association shall rely upon the designer for the following controls of construction:

1. He shall franchise reliable and skilled professional builders, and shall satisfy himself that their construction methods are adequate.

2. He shall certify all molds used in construction of hulls.

3. His approval shall be required for any modification in construction or materials proposed by any professional builders.

With the above critical features hopefully under benign and despotic control, the association measurer will be concerned with sail measurement, and with dimensions alterable by kit builders and tinkerers.

The following list of specifications and methods of measurement has the sanction of the designer. It covers all aspects of boat and sail measurement both for the sake of completeness, and in case of future need.

At present association measurers will be concerned only with those sections marked by the asterisk.

General requirements

(a) The tolerances allowed in measurement are intended only to accommodate minor building errors or distortion from age. Any intentional deviation from the design, or exploitation of the tolerances is prohibited.

(b) Notwithstanding anything in these rules, the ASA retains the power to refuse to grant a certificate to any boat which it considers to be unacceptable in materials, workmanship, or finish.

(c) The plans referred to mean the designers plans, a set of which will be held by the Chief Measurer.


(d) All hull lines shall be fair curves.

(e) The overall length of the boat including stem band, but excluding normal rudder hangers shall be not more than 20 feet and not less than 19 feet 11 inches between perpendiculars, measured with the boat sitting level on the center cases.

(f) Hull center lines, which shall be taken as the intersection of the projected sides at the keel shall be 8 feet apart (±1/2″). Beam overall shall not exceed 10 feet including rubbing strake.

(g) The keel rocker is measured from the datum line established by stretching a line along the center line of the hull passing 5-5/16″ below the center line at the transom and 3-7/16″ below the keel at station 2, and shall be 1″, 11/16″, 1-1/2″, and 4-3/16″ at stations 4, 6, 8, and 11 respectively, with a tolerance of ±1/2″. For measurement purposes, stations are taken vertically above the datum line as follows:

Station 2 15′ 10″ forward of the lower edge of transom

4 12′ 8″

6 9′ 6″

8 6′ 4″

11 1′ 9″

(h) The hulls are to conform to the plans within manufacturing tolerances. The hull section is controlled at stations 2, 4, 6, 8, and 11 by means of outside templates cut 3/4″ larger than true hull shape. Templates must be applied perpendicular to the datum line. The hull must be within 1/4″ of the templates, measured in the plane of the section with the template centrally placed and normal to the base line. The stem profile is similarly controlled by a template cut 3/8″ larger than the true shape except at 2″ below the sheer and at station 2 where it shall not be cut away and must touch the hull. The stem, including the stem band, must lie within 3/4″ of this template.

*(i) The vertical depth of the hull at stations 2, 4, 6, 8, 11 shall be 2′ 1″, 2′ 3‑5/8″, 2′ 2‑1/16″, 1′ 11‑11/16″ and 1′ 7″, measured from the intersection of the projected sides at the keel to top face of ply deck immediately over the topsides, with a tolerance of ±1/4″.

Deck and Cockpit Layout

(j) The hulls shall be completely decked at gunwale level, and hatches, if fitted, shall be in the decks aft of the rear beam, reasonably watertight and suitably held down for sailing.

*(k) The cockpit layout and beam structure shall be essentially as shown in the plans. The beam positions shall be as follows measured from the transom lower edge to main beam after face, 10′ 6″ (±1″), and to rear beam after face 3′ 3″ (±1″). The beam dimensions shall be as shown on the plans within normal fairing limits.

Rudders and Centerboards

*(l) The shape of the rudders and centerboards shall conform within tolerances of 1/2″ fore and aft and top to bottom to a master template made to designers specifications. Material is optional. Original section shall not exceed 0.0006 NASA section. Maximum thickness of boards shall not exceed 1-1/8″.

Center case

*(m) These must be parallel, in the center line of the hull, and not less than 3′ 6″, and not more than 4′ 2″ in length. Projected front end of the slot should be 9′ 6″ from the transom. Maximum width of slot shall be 1-3/8″.

Stem or keel bands

*(n) A stem or keel band may be fitted, not more than 1/2″ wide and 1/4″ deep.

Hull weight

*(o) The weight of the boat in dry condition to the satisfaction of the measurer shall not be less than 450 lbs. This weight is to include any fixtures essential to the sailing of the boat which are normally screwed, glued, or otherwise permanently fixed in place, including boards and excluding rudders.

Mast and boom

*(p) The mast shall be stepped on the main beam by means of a suitable step of maximum depth of 2-1/2″ below the mast heel pin, securely fixed to the boat immediately over the main beam. The mast shall be not more than 28′ 6″ (±1″). The mast heel pin shall not exceed 5/8″ in length. The weight of the mast with rigging and spreaders shall not be less than 50 lbs. Mast and boom shall be of uniform section end to end.

Dimensions for mast section: 3″ x 4-1/2″±1/4″

Leading edge round, radius 1-1/2″

Maximum wall thickness: 0.1000″ leading edge tapering to

0.090″ at web

0.070″ tunnel wall

0.075″ web, athwartships

Dimensions for boom section: 2-1/2″ x 3-3/8″±1/4″

Leading edge round, radius 1-1/4″

Maximum wall thickness: 0.080″ thick leading edge tapering to

0.062″ at the web

0.066″ tunnel wall

0.080″ web

Spars shall be straight when first measured. Purposely bent spars are prohibited.

*(q) Bands shall be applied as follows:

On the mast

No. 1 – A band, the lower edge of which shall be at the stop at the upper end of the tunnel, such stop to be no further than 28′ 3-1/2″ from the foot of the mast.

No. 2 – A band, the lower edge of which is 6″ below the lower edge of number 1.

No. 3 – A band, the lower edge of which is 26′ below the lower edge of number 1.

No. 4 – A band, the lower edge of which is 6″ below the lower edge of number 3.

On the boom

No. 5 – A band, the forward edge of which shall be 9′ 6″ from the projected after edge of the mast.

Bands 1 and 3 shall be of the same color. Bands 2 and 4 shall be of the same color and shall be of contrasting color with bands 1 and 3. All bands shall be of contrasting color with the spars.

When the mainsail is hoisted so that the top of the head board is at the lower edge of number 1, the projected upper edge of the boom shall not be below the lower edge of number 3.

When the mainsail is hoisted so that the top of the head board is at the lower edge of number 2, the projected upper edge of the boom shall not be below the lower edge of number 4.

The foot of the mainsail shall not extend beyond the inner edge of the band upon the boom.

Fixed goosenecks, if used in conjunction with loosefooted mainsails, shall be installed no lower than the lower edge of band 4. Such mainsails shall be down hauled such that the projected lower edge of the mainsail is not below band 3.

Mainsail measurement

*(r) The mainsail shall be measured on the boom with the battens in position. The foot shall first be stretched to the natural extent of the fabric to eliminate free material near the rope or to the black band, whichever occurs first. The luff shall then be stretched in the same manner to a maximum of 26′ 0″, and pegged down. The leech diagonal is then established as a line joining the forward upper edge of the boom black band and the intersection of the upper edge of the headboard and luff rope under 20 lbs. tension, and shall not exceed 27′ 6″ in length.

Roach offsets shall be measured at right angles to the leech diagonal starting from the head as follows:

0. 4-1/2″

1. 3′ 0″ down 1′ 9-1/2″ maximum offset

2. 6′ 6″ down 2′ 10″ maximum offset

3. 13′ 6″ down 3′ 3″ maximum offset

4. 20′ 6″ down 2′ 1/2″ maximum offset

The roach shall not extend beyond a fair curve through these points and the upper and lower endings of the leech diagonal.

One panel of the mainsail (approximately 2′ 3″ on the luff for traditional materials, or the full width of the sail cloth for newer materials) shall be red, and shall bear the class insignia upon it. The upper and lower edges of the red panel shall be approximately parallel to each other, and these edges shall be approximately perpendicular to the luff (with allowances made due to the cut of the sail cloth panels in fabrication of the sail). Its lower edge shall be located not lower than 11′ 8″ below the top of the headboard, nor higher than 6′ 14″ below the top of the headboard .

The number of battens installed in a mainsail is at the option of the sail maker.

The mainsail may be loose footed or shelf footed at the option of the sail maker.

The mainsail color may be any solid color which contrasts with the color of the red panel; however, it is recognized that the traditional color of the mainsail is white.

Foresail measurement

*(s) The maximum dimensions of the foresail, measured to the intersection of the projected sides shall be as follows:

Luff: 20′ 0″ Leech: 18′ 6″ Foot: 8′ 3″

The roach on the leech under no tension shall not exceed 2″. The roach on the foot shall not exceed 3″.

Not more than three battens, not to exceed 18″ in length, shall be permitted on the leech.

In the case of adjustable luffed jibs the stretched luff must be contained within the 20′ 0″ maximum by a permanently installed wire. The luff of jibs constructed of mylar are not required to have a permanently installed wire.

The foresail color may be any solid color; however, it is recognized that the traditional color of the foresail is white.


*(t) One forestay, two main shrouds and diamond stays must be fitted as shown in the plans. The shrouds must be connected to the gunwales not more than 2′ 1″ and not less than 1′ 11″ abaft the rear face of the main beam. The forestay shrouds must be attached directly to the mast and not more than 22′ 8″ nor less than 22′ 4″ above the lower end of the heel pin. The forestay tang shall be located 7′ 3/4″ ahead of the rear face of the main beam (±1″).

Spray deflectors

*(u) Spray deflectors are optional; however, when installed, spray deflectors of not more than 6′ 6″ nor less than 5′ 11″ shall be located as shown in the drawings, and shall project not more than three inches and not less than two inches from the hull.


*(v) The following items are prohibited:

a. Outriggers

b. Ballast in the boat or carried by the crew.

c. Any apparatus or contrivance other than the trapeze which might support or assist in supporting the crew or helmsman outboard.

d. Hydrofoils, except rudder blades or drop keels.

e. Spinnakers.

Revised and adopted August 1994